Telephone receiver



May 26, 1925.

C. E. VAWTER TELEPHONE RECEI VER il M y 1922 &" jaflyf/ Ewwamtoz m a Z/W @51 flbtozwews KW Lt- K k till thru the air gap.

L. E. VA'WTIER,

i TENT TELEE HQNE RECEIVER.

Application filed. Hay 23,

. known that l, CHARLES E. VAWTER, a citizen of th United States, residing at Phiiz'idciphia,in the county of Philadelphia, n of Pennsylvania, have invented certain new and useful improvements in Telepl'aon'o i teoeivei and i do hereby declare s following to be it full, clear, and exact the invention, such as will scription or others skilled in the art to which it erteins to niche and use the some.

his invention elates to improvements lephone receive 4 and more particularly iat'type by means of which the sound etttly snlplilied" .c ordinary type of telephone receiver prises principally an electroinagnet, a diaphragm oi .uragnetic material, end a permanent magnet, the diaphragm being supported in close proximity to one of the es oi the electromagnet. 'llhe permanent net creates an initial magnetic field in U air gap between the pole and the diaoiragni. 'llhis initial magnetic field is then ve ied by the voice currents flowing in the the electromegnet, the diaphragm be cause-d to vibrate by the variable attracforce which is exerted directly upon it This vibration of the diaphragm produces sound Waves which follow closely tllg lm ellllittlOllS of the voice eurre r making. a receiveno'f the loud speaking per it is desirable to use a diaphragm oi" i such as mice, which has better properties than the ordinary diain of magnetic material. it :3, nonagi'ietic diaphragm is used it must be con nested in some manner to El-Xllttgllbtlfi bar 3 armature in the field of the electroznsg The pulsating magnetic field causes the armature to vibrate, which, in turn,

' the diaphragm vibrate.

mane-s Various methods of producing diaphragm vibrations of large amplitude have been developed, Link niechenisnis have been used, the srrangenient being such that a coinnarativi y small movement oi the arn'iature rill pr duce a much larocr movement of the diaphragm. A typual arrangement consists oi an armature pivoted at one end and attached to the di: pbrapgm by a suitable link 1.; ie other 'cl l ll, The armature wit-h respect to the electroilzigllcb that the force is applied near the pivoted end, so that the motion of the end the armature 1922. Serial No. 562,962.

connected to the diaphragm is of greater amplitude than the motion ofthe part of adjacent to the clectromegnet. In another arrangement, a flexible arrow ture is used; one end of. the armature is lined and the other end is connected. to the diaphragm. In stiil another arrangement an armature is used, one end of which is connected to the diaphragm by at suitable link, the other end being supported by a spring. It is apparent that in toese various arrangements, the gain in amplitude is made at the expense oifthe force exerted by the (ZlECi-IOITHLgDQlZ, and consequently the ampliiieation depends upon the electromagnet.

One object of the presentinvention is to provide it combination otmcgnets which will give a maximum force on the armature for a, given megnetomotivo force n the present invention at suitably mounted diaphragm is provided, the diaphragm being connected to an armature preferably in such a manner that the armature is freely suspended The ends of thecrmature poles of a, magnet n hidi strength of the are adjacent the strongly magnetizes the armature. By this arrangemenuthe armature itself becomes a I magnet having poles cormsponding to the poles adjacent the ends thereof. A magnet is also provided at; each end of the armature" These magnets produce as magnetic field ct substantially right angles to the armature and diaphragm. The diaphragm is caused to vibrate by varying the magnetic field which acts upon the armature.

An embodiment of the invention is disclosed in the accompanying drawing in whicl1- Fig. l ,is a section view of a receiver showing the improved construction; and

Fig. 2 is a section View taken at right angles to the plane of Fig. 1.

Referring to the drawing, a case 1 of ordinary construction'is shown,- having a cap 2 suitably affixed thereto, as; by the screw threaded flange 3. .A born 4 is attached to the cap 2 for directing "the sound waves. The diaphragm 5 is secured in place betwcelrtwo rubber rings 6. This diaphragm 5 may be of any'suitable material, such as mica, and if desirable, the thickness of the diaphragm may vary from. the center to the edge, depending upon the results de ill) (Ill

vary with her or link 8 fixed to thearmature and held in place by any suitable means, as by the screw 9 passing through the diaphragm. As shown in the drawing, the link 8 is a single straight member, and neither the link nor the armature is pivoted in any way. The armature 7 which is of magnetic material is preferably rectangular in cross section and ot' a length substantially greater than its width. The connecting member or link 8 should be'made of light material in order to lessen the inertia of the movingparts, and should be of large enough cross section at the point of contact with the diaphragm to brace the armature against longitudinal motion, the armature being freely suspended by the link 8.

A U-shaped magnet 10 havin inwardly projecting poles 11 and 11' is fastened to the casing the screws 12. This U-shaped magnet 10 is so situated with respect to the diaph'ra m 5 and the armature 7 attached thereto, tiat the poles 11 and 11 are directly opposite the ends of the armature 7. The U-magnet 10 may .be a permanent magnet or it may be an electremagnet having a coil 13 mounted thereon. F'This coil 13 may carry a direct current, in which case the magnet 10 acts as a strongpermanent magnet, or it may carry a varying current, in which case the flux across the gaps between the poles 11 and 11', and the armature 7 will the current.

At the end of the armature 7 adjacent the pole 11 of the U-magnet 10, there is a magnet 14 arranged at substantially right angles to the armature 7 and fastened to the case 1 by a screw 16. The shape of this magnet is shown in Fig. 2. It is pref-' erably made in two parts which may be any suitable manner as by the screw '16. Two coils 17 are shown mounted on the legs of this magnet 14, the

coils being preferably connected in series.

The number ofthe coils and their arrangement are immaterial, provided the coils are adapted to produce the necessary magnetomotive force. The two poles 18 and 18' of the magnet 11 are situated on opposite of the armature 7 so that air gaps are'forme between the poles, and the end of the armature 7 these gaps being large enough so that when the armature is vibrating it does not come in contact with either of the poles 18 and 18. The flux between 'these poles passes through the end of the armature at substantially right angles thereto.

At the end of the armature 7 adjacent the pole 11 of the U-magnet 10, there is a second magnet 15 exactly like the. magnet 14- described above. This magnet 15 is mounted in the casein the same manner as the magnet 14 and carries two coils 19 in se- 1 in any-suitable manner, as by sides d pole 18 and the It is to be undcrstoml that the particularv shape of the magnets 14 and 15 not im portant and any suitable magi'ictic struc turc may be employed. 7

As mentioned above, the diaphragm is caused to vibrate by varying the magnetic field in the vicinity of the armature in such a manner that forces are exerted on the armature at right angles thereto. In one form of my invention, the magnet 10 is a permanent magnet. The leads of the coils 13 on this magnet are connected to a source of direct current, or this coil may be dispensed with if the permanent magnetization is strong enough to secure the desired result. The effect of this magnet 10 is to strongly magnetize the armature 7. The leads of the coils 17 and 19 on the magnets 14 and 15 may be directly connected to the line carrying the varying voice current, or they may be connected to the secondarylof a transformer in thevoicecurrent circuit. If the latter connection is used, the current flowing in the coils .17 and 19 will be an alternating current.

At a certain instant, the current in the coils 17 and 19 will be in the direction to make the pole 18 a south pole, and the pole 18' a north pole asshown in ig. 1 by the letters'S and N respectively. The connection between the coils 17 and 19 is such that at this given instant the .pole 20 is a north pole and pole 20' is a south pole. It the magnetization of'the permanent magnetlO issuch that the poles 11 and 11' are north and south poles respectively then the magnetization of the armature 7 will be as indicated in Fig. 1, that is, the end of the armature adjacent the north pole 11 will be a south pole and the opposite end a north pole. Thus, with the polarities as indicated in Fig. 1, there will be a force of attraction between the north pole 18 of the electromagnet 14 and the armature, and there will be a force of repulsion between the south armature. A double force will also act on the armature 7 between the poles 20 and 20 of the electromagnet 15, by virtue of thehttraction between the armature and the south pole 20 and the repulsion between the ai'mature and the north pole 20. The net eii'eet is therefore a very strong force acting on the wards the poles 18' ly, the diaphragm and 20 and, according- 5 is distended toward the horn 4.

armature to move it tothe i 'JPlS iciin upon the molecule, and the mic 7 does not change for iihe polarity of the ngnei; 10 remains the some, i

"Y end are connecied d1- ii. inc coiis 1 VM rcctiy o ii-he vo'cc current circuit then ihe viii 11g cnii'ent in these coils is n puissting In current, and the polarity of the cicci'i-oinagnets 1.4.- and 15 is not. reversed, The fin between ihc poies of these magnets varies, however, with the pulsations of the curl-c1112 a d series of unidirectional im puises are transni'itced to the diaphragm 5,. ivhei'ci y this diaphragm is caused to vibrate.

in another: mode of operation, the magi lei and 15 are used as permanent mag and if the coiis 1'? and ii! are used, they 1 The coil 13 on 'ihe nnnnci; 10 is conncctcd to the voicefcin i (ii in the secondary of s trnnsfoi'iiier. nitcrnsiing current is flowing in the coil 5} of the U-nnignoi 10, at in certain instantixhc polarity of the various elements Wiii be as rcpi'cscnicd in Fig, 1 and the miniature \vi-ii ho moved fow: 1d the poles 18 and 20. fit ii intci instant, when the current in the rscd, the polarity of the U-nnigwiii he 'cvci'scd and this reverses the "v the iirinmtni'c. Since the poi-inoi inc megncts i i and 15 remains onisngcd, iaho iii'ninizni'e will now he forced This is s sis,

-y direct current.

x :13 from the poles i8 and 20' due to izhe icci; cm the end of the'ni'nmtuce adjacent :hc n'nignct idis now a north poic zqn'i is therefore repelled by the north pole 18" and :z-itcuctcd by the south poic l8; and H10 the Oiiifil end of the armature LL corms coding manner.

"he coii l I is connccizec directly to the circuits, then it czimies o pnh ovens, and 'shc cii ect is to i o; the poles ii and 11 I niagneiicantion of the an I however, i'eveising the; i n'ients. When the; cm-

' is n maximum, the pole .10 end the mag- 4 ilfmfii'iii'fi "iii heinnxiinnm, :ecncrted on she ei'inntnrc by A end iii Wiii. eiso he s moxiicon. ihecnvrsnt in the coii i3 is o 'nsn, the poies Iii and iii "wiii he vvenk 7 1c force on the Wczikiy nm nciizcd on [151 c iviii no minimum. This vni'iaiion s the nrnisiiure prodncesthe vibraf the diaphragm.

This invention includes e sirongdy meg noticed nriinitnic, freely suspended from a dinnhm 'in and n phirsiiiy of magnets on: ed so that the in between the poles of exerted on the mind r i scenes awn of the magnets passes thi'ough the ends hire for e given amount of energy supplied to ins ciect-roan'agnefi, than can he applied by any c wengeinent of magnets heretofore employed.

it to understood that this invention may he applied to teicphone transmitters cs ivcii as receivers, and, accordingly the invenizion is not limited in this respect.

Itj'is apparent that the arrangement, size and proportions of the parts may be varied Without departing-from the principle of the invention which is not confined to the pan i/ICHi -SJE' embodiments shown and described,

but is intended to cover'suchmodifications thereof as fall Within the pending; claims.

I ciaiin:

1. A device of the character described comprising a, diaphragm, an armature di-i rectiy connecied thereto and freeiy suspended therefrom, a magnet at each end of said armature for cxertin a magnetic force on said armature at right angles thereto, czich of said magnets having two poles on opposite sides'of the armature, and means separate from said magnet for strongly magnetizing sold armature.

2. A ,device of the character described comprising a diaphragm, an nrinafinre con nccied thereto, a magnet at each end of said armature for exerting a magnetic force on each pole of said armature, each of said magnets having two poles on opposite sides of said armature and means separate from said magncis for strongly magnetizing said armature.

3. A device of the character described.

scope of the op comprising a diaphragm, an armature c0nncctcd thereto, a magnet at each end of said armature for exerting z 'magnetic force on each pole of said armature, said forces act ing co move each end oi said armature in the some direction and means separate from said magnets for strongly nmgnetizing said armature,

A device oi the character described comprising a diaphragm, an armature diiecsiy connected to said diaphragm and fmciy suspended therefrom, e magnet for producing n strong constant magnetization of said ci'niecure, and a, magnet at each end of said armature and having two poles on opposite sides thereof for producing a magneticiinx. piissing through each end of said n'mgnctized armature at snhstontially right ci'igies ihercco, whereby said diepiiiegin is ccusedfio vihcnte,

5. A, device of the character described comprising a diaphragm, an armature directi y connected to said diaphragm and freely suspended therefromfinccns at each end of said armature for producing a vary- \ing nmgnctic force on each poie of said nccted to said diaphragm, an electromagnct at each end of said-armature arranged at substantially right angles thereto and having two poles on opposite sides oi said armature, the coils of said electroinagnct being adapted to carry voice -"currcnts for producin c a varyingmagnetic field acting upon the poles of said arn'iatuil'c for vibrating said diaphragm, and a magnet for producing a strong magnetization o i' said armature.

7. A device of the character describe-d comprising a diaphragm, an armature, a single straight link connecting'said armature to said diaphragm and freely suspending the armature from the diaphragm, an clcctromagnet at each end of said armature arranged at substantially right angles thereto and having two poles on opposite sides of said armature, eachelcctronuignet comprising a magnetic core and a coil for carrying varying currents for producing a varying magnetic field acting upon the armature pole adjacent thereto the coils'of i I 1,539,005 a said eleetromagnets being so connected that the'varying magnetic forces acting upon said armature tend to move each end of said armature in the same direction and a inagnctior producing a strong: magnetization of said armature.

8. A device of the character described. comprising a diaphragm, an armature, a single straight link connecting said armaturc to said diaphragm and freely suspending said armature from the diaphragm, said magucl comprising a magnetic core and a coil for carrying a constant-direct current and an electron'iagnet at each end-of said armature, arranged at substantially right anglcs thcrcto, each of said electromagnets comprisinga magnetic core and coils. for carrying -voice currents and having two poles on opposite sides of said armature,- the coils of said electromagnets being coir nected in series in such a manner that the varying magnetic fields produced by the voice currents act in unison to move each end of'said armature in the same direction and a magnet for producing astrong mag netization of said armature.

1n testimony'wher'eof I afiixiny signature.

CHARLES E.-VAW.TICR. 

